was it micky who looped a grand slam or upkeep lanc ? I seem to recall grand slam due to the extra power of the engines and being stripped out so much to gain the range... but uncle al might be playing tricks
seem to remember a tale being told about some years ago
I read an article many moons ago about one of the upkeep Lancs an air test after it had been stripped of weight for the raid, a B-17 came up behind it and they would normally leave the Lanc standing, the Lanc pilot throttled back to allow him to pull level then opened it up and barrel rolled it around the B-17 before leaving the stunned B-17 crew behind